The present disclosure relates to a to-be-charged apparatus having a battery, a charging adapter used in charging the to-be-charged apparatus, an electronic apparatus set including the to-be-charged apparatus and the charging adapter, and a plug unit provided in the to-be-charged apparatus.
An earphone gender for a multimedia apparatus disclosed in Japanese Patent Application Laid-open No. 2008-259192 (hereinafter, referred to as Patent Document 1) includes a stem (6), a code (11), and a USB (Universal Serial Bus) connector (12) as shown in FIGS. 1, 2, and 14. A multimedia apparatus (100) is connectable to the stem (6), and earphones (200) are connectable to an audio socket (22) integrally provided to the USB connector (12). Such an apparatus enables the multimedia apparatus (100) to be connected to an external apparatus such as a PC (Personal Computer) via a path leading from the USB connector (12) to a dock connector (5), and thus charging and data transmissions with respect to the multimedia apparatus (100) become possible (see, for example, paragraph [0023] in specification of Patent Document 1).